James t



(No Model.)

J. T. HAYDEN.

SAFETY VALVE.

Patented Apr. 28, 1891.

Q N N R 1 m we A w o W I w i TATES ATENT Price.

THE CRANE COM- PANY, OF ILLINOIS.

SAFETY-VALVE.

SPECIFICATION forming part of Letters Patent No. 451,210, dated April28, 1891. Application filed January 31, 1891. Serial No. 379,764. (Nomodel.)

To a, whom it may concern.-

Be it known that I, JAMES T. HAYDEN, of Chicago, in the county of Cookand State of Illinois, have invented certain new and useful Improvementsin Safety-Valves, of which the following is a specification.

The objectof my inventionis to provide an ample area or opening for theescape of steam when the valve is open and to insure the prompt andcertain closure of the valve when the steam-pressure has beensufficiently relieved, and to make the valve sufficiently sensitive toconfine the fluctuations of steampressure to a comparatively smallrange.

In the operation of safety-valves there are two conflicting conditionsto fulfill, one condition being that the escaping steam shall so actuponthe safety-valve when lifting as to insure a wide opening, so thatthe steam may escape as rapidlyas it is generated within the boiler. ingforce of the steam shall not be so great as to prevent the seating ofthe valve when the pressure of steam within the boiler has been reducedto the desired Working pressure. In the presentinvention I have providedfor the fulfillment of these two conditions by the use of an auxiliarydisk or valve combined with the main Valve in a manner which willhereinafter be described.

The further object of my invention is to provide a valve-exit for thesteam from the casing, so that the parts within the casing may beprotected from dirt and consequent derangement.

In the accompanying drawings, Figure l is a vertical section of a valveconstructed in accordance with my invention. Fig. 2 is a similar sectionshowing the valve open. Fig. 3 is a plan View of the valve properseparated from its casing. Fig. 4 isan inverted plan of the same.

In the drawings, A is the valve-casing,which, so far as the first partof myinvention is concerned, may be of any well-known form. It is, asshown herein, however, closed except upon one side, where an exit a, towhich the escape-pipe may be screwed, is provided, as shown in Fig. 2,while in Fig. l the exit is provided with a flap or valve, hereinaftermore valve-body,

The other condition is that the liftminutely described, which makes thecasing tight when not open for the escaping steam.

Within the casing is provided a valve-seat B, of the ordinary form, towhich is fitted a valve C. Said valve C is held to its seat by a spindleD, upon which rests a spring E. The tension of spring E is adjusted bythe screw-cap F, attached to the upper part of the r and an outer casingor shield G, which is fitted over the screw-cap F and the upper portionof thevalve-casing, shelters the parts and is customarily locked inplace, so that unauthorized tampering with the adj ustment of the valveis prevented.

The devices for retaining and housing the valve just described are notclaimed to be novel, and, so far as my present invention is concerned,may be modified indefinitely without departing from my invention, whichrelates especially to the portions hereinafter described.

The valve C is provided with an extended face outside of the beveledbearing portion of the valve-seat B, and the outer edge of this extendedface is bounded by a depending lip C, which, when the valve is closed,slightly overlaps the valve-seat. From this extended face a series ofperforations c extend to the upper face of the valve C, as shown inFigs.

1, 2, and 4:. Resting upon said upper face of main valve C is animperforate auxiliary valve H, for which the main valve forms a seat.Said auxiliary valve H is so fitted upon the main valve C as to closethe perforations 0 when it is down. It is held in contact with the valveC by a spring I, Which spring is compressed by a nut J upon the upperpor tion of the spindle K, forminga part of or attached to the mainvalve C. Said nut J is held, when adjusted, by a pin L, which is droppedinto the opening formed by a notch cut into the spindle K, and one ofthe series of notches Z cut into the nut J, which is brought to coincidewith the first-named notch.

The operation of the valve C and its auxil- 5 iary valve H is obviousfrom the foregoing description and a comparison of Figs. 1 and 2. WVhenthe steam-pressure rises beyond the point to which the valve is set, thelatter is raised and the escaping steam, entering the orifices c, raisesthe auxiliary valve H, there being thus provided an additional outletfor the escape of the steam. The use of the auxiliary valve is found toinsure the prompt closure of the main valve upon a slight fall of thesteam-pressure, whether the valve be set for a high or a low pressure,thus adapting a single valve to use under a widely-varying working pressure,it desired. The resistance of the valve to closure is diminishedby the rise of the auxiliary disk, and there is available a greaterforce for opening the valve than subsequently exists to prevent itsclosu re. Its speedy and complete closure thus ensues after acomparatively small reduction of the steam-pressure.

In Fig. l a clack-valve M is shown hinged to one side of the exit of thevalve-case. It is held in contact with the valve-case by a light springm, which allows the valve to open under. a very small pressure, butkeeps the valve M snugly closed when the safety-valve is closed.

Having fully described my invention, what I claim, and desire to secureby Letters Patent,

1. The combination, in a safety-valve, of a perforated main valve and animperforate auxiliary valve seated upon the main valve, substantially asdescribed.

2. The combination, in a safety-valve, of a main valve having anextended surface beyond the portion in contact with the valveseat and alip surrounding said extended surface and overlapping the raised portionof the valve-seat, said main valve having perforations extending fromthe extended surface to the upper side of the valve, and an imperforateauxiliary valve seated upon said main valve, substantially as described.

3. The combination, in a safety-valve, of a valve-casing having itsescape-orifice beyond the safety-valve proper provided with a valvewhich closes the valve-case tightly when the main valve is notinoperation, substantially as described.

4. The combination, in main valve having an extended surface beyond theportion which makes contact with the valve-seat, and having perforationsfrom said extended surface to the top of the valve, and an imperforateauxiliary valve adapted to close said orifices and to be raised by theescaping steam when the main valve is lifted, substantially asdescribed.

JAMES T. HAYDEN.

Witnesses:

IRWIN VEEDER, 'Fonn MASON.

a safety-valve, of a-

